A projector projecting a projection-use image displayed on a liquid crystal device is known in the art (for example, Japanese Patent Laid-open Publication No. 2005-250392A). In this projector, only a specific polarization component of light is used for projection of the projection-use image, so only half of the amount of light emitted from a light source can be utilized. Therefore, a projector using a polarization conversion device to align the light emitted from a light source in polarization direction with a certain polarization direction and thereby increase the amount of light able to be used for projection by the projector has been proposed (for example, Japanese Patent Laid-open Publication No. 2006-227361A).